<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.audio.mp3.php                                        //
// module for analyzing MP3 files                              //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////


// number of frames to scan to determine if MPEG-audio sequence is valid
// Lower this number to 5-20 for faster scanning
// Increase this number to 50+ for most accurate detection of valid VBR/CBR
// mpeg-audio streams
define('GETID3_MP3_VALID_CHECK_FRAMES', 35);


class getid3_mp3 extends getid3_handler
{

    public $allow_bruteforce = false; // forces getID3() to scan the file byte-by-byte and log all the valid audio frame headers - extremely slow, unrecommended, but may provide data from otherwise-unusuable files

    public function Analyze()
    {
        $info = & $this->getid3->info;

        $initialOffset = $info['avdataoffset'];

        if (!$this->getOnlyMPEGaudioInfo($info['avdataoffset'])) {
            if ($this->allow_bruteforce) {
                $info['error'][] = 'Rescanning file in BruteForce mode';
                $this->getOnlyMPEGaudioInfoBruteForce($this->getid3->fp, $info);
            }
        }


        if (isset($info['mpeg']['audio']['bitrate_mode'])) {
            $info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);
        }

        if (((isset($info['id3v2']['headerlength']) && ($info['avdataoffset'] > $info['id3v2']['headerlength'])) || (!isset($info['id3v2']) && ($info['avdataoffset'] > 0) && ($info['avdataoffset'] != $initialOffset)))) {

            $synchoffsetwarning = 'Unknown data before synch ';
            if (isset($info['id3v2']['headerlength'])) {
                $synchoffsetwarning .= '(ID3v2 header ends at ' . $info['id3v2']['headerlength'] . ', then ' . ($info['avdataoffset'] - $info['id3v2']['headerlength']) . ' bytes garbage, ';
            } elseif ($initialOffset > 0) {
                $synchoffsetwarning .= '(should be at ' . $initialOffset . ', ';
            } else {
                $synchoffsetwarning .= '(should be at beginning of file, ';
            }
            $synchoffsetwarning .= 'synch detected at ' . $info['avdataoffset'] . ')';
            if (isset($info['audio']['bitrate_mode']) && ($info['audio']['bitrate_mode'] == 'cbr')) {

                if (!empty($info['id3v2']['headerlength']) && (($info['avdataoffset'] - $info['id3v2']['headerlength']) == $info['mpeg']['audio']['framelength'])) {

                    $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';
                    $info['audio']['codec'] = 'LAME';
                    $CurrentDataLAMEversionString = 'LAME3.';

                } elseif (empty($info['id3v2']['headerlength']) && ($info['avdataoffset'] == $info['mpeg']['audio']['framelength'])) {

                    $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';
                    $info['audio']['codec'] = 'LAME';
                    $CurrentDataLAMEversionString = 'LAME3.';

                }

            }
            $info['warning'][] = $synchoffsetwarning;

        }

        if (isset($info['mpeg']['audio']['LAME'])) {
            $info['audio']['codec'] = 'LAME';
            if (!empty($info['mpeg']['audio']['LAME']['long_version'])) {
                $info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['long_version'], "\x00");
            } elseif (!empty($info['mpeg']['audio']['LAME']['short_version'])) {
                $info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['short_version'], "\x00");
            }
        }

        $CurrentDataLAMEversionString = (!empty($CurrentDataLAMEversionString) ? $CurrentDataLAMEversionString : (isset($info['audio']['encoder']) ? $info['audio']['encoder'] : ''));
        if (!empty($CurrentDataLAMEversionString) && (substr($CurrentDataLAMEversionString, 0, 6) == 'LAME3.') && !preg_match('[0-9\)]', substr($CurrentDataLAMEversionString, -1))) {
            // a version number of LAME that does not end with a number like "LAME3.92"
            // or with a closing parenthesis like "LAME3.88 (alpha)"
            // or a version of LAME with the LAMEtag-not-filled-in-DLL-mode bug (3.90-3.92)

            // not sure what the actual last frame length will be, but will be less than or equal to 1441
            $PossiblyLongerLAMEversion_FrameLength = 1441;

            // Not sure what version of LAME this is - look in padding of last frame for longer version string
            $PossibleLAMEversionStringOffset = $info['avdataend'] - $PossiblyLongerLAMEversion_FrameLength;
            fseek($this->getid3->fp, $PossibleLAMEversionStringOffset);
            $PossiblyLongerLAMEversion_Data = fread($this->getid3->fp, $PossiblyLongerLAMEversion_FrameLength);
            switch (substr($CurrentDataLAMEversionString, -1)) {
                case 'a':
                case 'b':
                    // "LAME3.94a" will have a longer version string of "LAME3.94 (alpha)" for example
                    // need to trim off "a" to match longer string
                    $CurrentDataLAMEversionString = substr($CurrentDataLAMEversionString, 0, -1);
                    break;
            }
            if (($PossiblyLongerLAMEversion_String = strstr($PossiblyLongerLAMEversion_Data, $CurrentDataLAMEversionString)) !== false) {
                if (substr($PossiblyLongerLAMEversion_String, 0, strlen($CurrentDataLAMEversionString)) == $CurrentDataLAMEversionString) {
                    $PossiblyLongerLAMEversion_NewString = substr($PossiblyLongerLAMEversion_String, 0, strspn($PossiblyLongerLAMEversion_String, 'LAME0123456789., (abcdefghijklmnopqrstuvwxyzJFSOND)')); //"LAME3.90.3"  "LAME3.87 (beta 1, Sep 27 2000)" "LAME3.88 (beta)"
                    if (empty($info['audio']['encoder']) || (strlen($PossiblyLongerLAMEversion_NewString) > strlen($info['audio']['encoder']))) {
                        $info['audio']['encoder'] = $PossiblyLongerLAMEversion_NewString;
                    }
                }
            }
        }
        if (!empty($info['audio']['encoder'])) {
            $info['audio']['encoder'] = rtrim($info['audio']['encoder'], "\x00 ");
        }

        switch (isset($info['mpeg']['audio']['layer']) ? $info['mpeg']['audio']['layer'] : '') {
            case 1:
            case 2:
                $info['audio']['dataformat'] = 'mp' . $info['mpeg']['audio']['layer'];
                break;
        }
        if (isset($info['fileformat']) && ($info['fileformat'] == 'mp3')) {
            switch ($info['audio']['dataformat']) {
                case 'mp1':
                case 'mp2':
                case 'mp3':
                    $info['fileformat'] = $info['audio']['dataformat'];
                    break;

                default:
                    $info['warning'][] = 'Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "' . $info['audio']['dataformat'] . '"';
                    break;
            }
        }

        if (empty($info['fileformat'])) {
            unset($info['fileformat']);
            unset($info['audio']['bitrate_mode']);
            unset($info['avdataoffset']);
            unset($info['avdataend']);
            return false;
        }

        $info['mime_type'] = 'audio/mpeg';
        $info['audio']['lossless'] = false;

        // Calculate playtime
        if (!isset($info['playtime_seconds']) && isset($info['audio']['bitrate']) && ($info['audio']['bitrate'] > 0)) {
            $info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['audio']['bitrate'];
        }

        $info['audio']['encoder_options'] = $this->GuessEncoderOptions();

        return true;
    }


    public function GuessEncoderOptions()
    {
        // shortcuts
        $info = & $this->getid3->info;
        if (!empty($info['mpeg']['audio'])) {
            $thisfile_mpeg_audio = & $info['mpeg']['audio'];
            if (!empty($thisfile_mpeg_audio['LAME'])) {
                $thisfile_mpeg_audio_lame = & $thisfile_mpeg_audio['LAME'];
            }
        }

        $encoder_options = '';
        static $NamedPresetBitrates = array(16, 24, 40, 56, 112, 128, 160, 192, 256);

        if (isset($thisfile_mpeg_audio['VBR_method']) && ($thisfile_mpeg_audio['VBR_method'] == 'Fraunhofer') && !empty($thisfile_mpeg_audio['VBR_quality'])) {

            $encoder_options = 'VBR q' . $thisfile_mpeg_audio['VBR_quality'];

        } elseif (!empty($thisfile_mpeg_audio_lame['preset_used']) && (!in_array($thisfile_mpeg_audio_lame['preset_used_id'], $NamedPresetBitrates))) {

            $encoder_options = $thisfile_mpeg_audio_lame['preset_used'];

        } elseif (!empty($thisfile_mpeg_audio_lame['vbr_quality'])) {

            static $KnownEncoderValues = array();
            if (empty($KnownEncoderValues)) {

                //$KnownEncoderValues[abrbitrate_minbitrate][vbr_quality][raw_vbr_method][raw_noise_shaping][raw_stereo_mode][ath_type][lowpass_frequency] = 'preset name';
                $KnownEncoderValues[0xFF][58][1][1][3][2][20500] = '--alt-preset insane'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues[0xFF][58][1][1][3][2][20600] = '--alt-preset insane'; // 3.90.2, 3.90.3, 3.91
                $KnownEncoderValues[0xFF][57][1][1][3][4][20500] = '--alt-preset insane'; // 3.94,   3.95
                $KnownEncoderValues['**'][78][3][2][3][2][19500] = '--alt-preset extreme'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues['**'][78][3][2][3][2][19600] = '--alt-preset extreme'; // 3.90.2, 3.91
                $KnownEncoderValues['**'][78][3][1][3][2][19600] = '--alt-preset extreme'; // 3.90.3
                $KnownEncoderValues['**'][78][4][2][3][2][19500] = '--alt-preset fast extreme'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues['**'][78][4][2][3][2][19600] = '--alt-preset fast extreme'; // 3.90.2, 3.90.3, 3.91
                $KnownEncoderValues['**'][78][3][2][3][4][19000] = '--alt-preset standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
                $KnownEncoderValues['**'][78][3][1][3][4][19000] = '--alt-preset standard'; // 3.90.3
                $KnownEncoderValues['**'][78][4][2][3][4][19000] = '--alt-preset fast standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
                $KnownEncoderValues['**'][78][4][1][3][4][19000] = '--alt-preset fast standard'; // 3.90.3
                $KnownEncoderValues['**'][88][4][1][3][3][19500] = '--r3mix'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues['**'][88][4][1][3][3][19600] = '--r3mix'; // 3.90.2, 3.90.3, 3.91
                $KnownEncoderValues['**'][67][4][1][3][4][18000] = '--r3mix'; // 3.94,   3.95
                $KnownEncoderValues['**'][68][3][2][3][4][18000] = '--alt-preset medium'; // 3.90.3
                $KnownEncoderValues['**'][68][4][2][3][4][18000] = '--alt-preset fast medium'; // 3.90.3

                $KnownEncoderValues[0xFF][99][1][1][1][2][0] = '--preset studio'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
                $KnownEncoderValues[0xFF][58][2][1][3][2][20600] = '--preset studio'; // 3.90.3, 3.93.1
                $KnownEncoderValues[0xFF][58][2][1][3][2][20500] = '--preset studio'; // 3.93
                $KnownEncoderValues[0xFF][57][2][1][3][4][20500] = '--preset studio'; // 3.94,   3.95
                $KnownEncoderValues[0xC0][88][1][1][1][2][0] = '--preset cd'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0xC0][58][2][2][3][2][19600] = '--preset cd'; // 3.90.3, 3.93.1
                $KnownEncoderValues[0xC0][58][2][2][3][2][19500] = '--preset cd'; // 3.93
                $KnownEncoderValues[0xC0][57][2][1][3][4][19500] = '--preset cd'; // 3.94,   3.95
                $KnownEncoderValues[0xA0][78][1][1][3][2][18000] = '--preset hifi'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0xA0][58][2][2][3][2][18000] = '--preset hifi'; // 3.90.3, 3.93,   3.93.1
                $KnownEncoderValues[0xA0][57][2][1][3][4][18000] = '--preset hifi'; // 3.94,   3.95
                $KnownEncoderValues[0x80][67][1][1][3][2][18000] = '--preset tape'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0x80][67][1][1][3][2][15000] = '--preset radio'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0x70][67][1][1][3][2][15000] = '--preset fm'; // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
                $KnownEncoderValues[0x70][58][2][2][3][2][16000] = '--preset tape/radio/fm'; // 3.90.3, 3.93,   3.93.1
                $KnownEncoderValues[0x70][57][2][1][3][4][16000] = '--preset tape/radio/fm'; // 3.94,   3.95
                $KnownEncoderValues[0x38][58][2][2][0][2][10000] = '--preset voice'; // 3.90.3, 3.93,   3.93.1
                $KnownEncoderValues[0x38][57][2][1][0][4][15000] = '--preset voice'; // 3.94,   3.95
                $KnownEncoderValues[0x38][57][2][1][0][4][16000] = '--preset voice'; // 3.94a14
                $KnownEncoderValues[0x28][65][1][1][0][2][7500] = '--preset mw-us'; // 3.90,   3.90.1, 3.92
                $KnownEncoderValues[0x28][65][1][1][0][2][7600] = '--preset mw-us'; // 3.90.2, 3.91
                $KnownEncoderValues[0x28][58][2][2][0][2][7000] = '--preset mw-us'; // 3.90.3, 3.93,   3.93.1
                $KnownEncoderValues[0x28][57][2][1][0][4][10500] = '--preset mw-us'; // 3.94,   3.95
                $KnownEncoderValues[0x28][57][2][1][0][4][11200] = '--preset mw-us'; // 3.94a14
                $KnownEncoderValues[0x28][57][2][1][0][4][8800] = '--preset mw-us'; // 3.94a15
                $KnownEncoderValues[0x18][58][2][2][0][2][4000] = '--preset phon+/lw/mw-eu/sw'; // 3.90.3, 3.93.1
                $KnownEncoderValues[0x18][58][2][2][0][2][3900] = '--preset phon+/lw/mw-eu/sw'; // 3.93
                $KnownEncoderValues[0x18][57][2][1][0][4][5900] = '--preset phon+/lw/mw-eu/sw'; // 3.94,   3.95
                $KnownEncoderValues[0x18][57][2][1][0][4][6200] = '--preset phon+/lw/mw-eu/sw'; // 3.94a14
                $KnownEncoderValues[0x18][57][2][1][0][4][3200] = '--preset phon+/lw/mw-eu/sw'; // 3.94a15
                $KnownEncoderValues[0x10][58][2][2][0][2][3800] = '--preset phone'; // 3.90.3, 3.93.1
                $KnownEncoderValues[0x10][58][2][2][0][2][3700] = '--preset phone'; // 3.93
                $KnownEncoderValues[0x10][57][2][1][0][4][5600] = '--preset phone'; // 3.94,   3.95
            }

            if (isset($KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']])) {

                $encoder_options = $KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];

            } elseif (isset($KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']])) {

                $encoder_options = $KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];

            } elseif ($info['audio']['bitrate_mode'] == 'vbr') {

                // http://gabriel.mp3-tech.org/mp3infotag.html
                // int    Quality = (100 - 10 * gfp->VBR_q - gfp->quality)h


                $LAME_V_value = 10 - ceil($thisfile_mpeg_audio_lame['vbr_quality'] / 10);
                $LAME_q_value = 100 - $thisfile_mpeg_audio_lame['vbr_quality'] - ($LAME_V_value * 10);
                $encoder_options = '-V' . $LAME_V_value . ' -q' . $LAME_q_value;

            } elseif ($info['audio']['bitrate_mode'] == 'cbr') {

                $encoder_options = strtoupper($info['audio']['bitrate_mode']) . ceil($info['audio']['bitrate'] / 1000);

            } else {

                $encoder_options = strtoupper($info['audio']['bitrate_mode']);

            }

        } elseif (!empty($thisfile_mpeg_audio_lame['bitrate_abr'])) {

            $encoder_options = 'ABR' . $thisfile_mpeg_audio_lame['bitrate_abr'];

        } elseif (!empty($info['audio']['bitrate'])) {

            if ($info['audio']['bitrate_mode'] == 'cbr') {
                $encoder_options = strtoupper($info['audio']['bitrate_mode']) . ceil($info['audio']['bitrate'] / 1000);
            } else {
                $encoder_options = strtoupper($info['audio']['bitrate_mode']);
            }

        }
        if (!empty($thisfile_mpeg_audio_lame['bitrate_min'])) {
            $encoder_options .= ' -b' . $thisfile_mpeg_audio_lame['bitrate_min'];
        }

        if (!empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']) || !empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'])) {
            $encoder_options .= ' --nogap';
        }

        if (!empty($thisfile_mpeg_audio_lame['lowpass_frequency'])) {
            $ExplodedOptions = explode(' ', $encoder_options, 4);
            if ($ExplodedOptions[0] == '--r3mix') {
                $ExplodedOptions[1] = 'r3mix';
            }
            switch ($ExplodedOptions[0]) {
                case '--preset':
                case '--alt-preset':
                case '--r3mix':
                    if ($ExplodedOptions[1] == 'fast') {
                        $ExplodedOptions[1] .= ' ' . $ExplodedOptions[2];
                    }
                    switch ($ExplodedOptions[1]) {
                        case 'portable':
                        case 'medium':
                        case 'standard':
                        case 'extreme':
                        case 'insane':
                        case 'fast portable':
                        case 'fast medium':
                        case 'fast standard':
                        case 'fast extreme':
                        case 'fast insane':
                        case 'r3mix':
                            static $ExpectedLowpass = array(
                                'insane|20500' => 20500,
                                'insane|20600' => 20600, // 3.90.2, 3.90.3, 3.91
                                'medium|18000' => 18000,
                                'fast medium|18000' => 18000,
                                'extreme|19500' => 19500, // 3.90,   3.90.1, 3.92, 3.95
                                'extreme|19600' => 19600, // 3.90.2, 3.90.3, 3.91, 3.93.1
                                'fast extreme|19500' => 19500, // 3.90,   3.90.1, 3.92, 3.95
                                'fast extreme|19600' => 19600, // 3.90.2, 3.90.3, 3.91, 3.93.1
                                'standard|19000' => 19000,
                                'fast standard|19000' => 19000,
                                'r3mix|19500' => 19500, // 3.90,   3.90.1, 3.92
                                'r3mix|19600' => 19600, // 3.90.2, 3.90.3, 3.91
                                'r3mix|18000' => 18000, // 3.94,   3.95
                            );
                            if (!isset($ExpectedLowpass[$ExplodedOptions[1] . '|' . $thisfile_mpeg_audio_lame['lowpass_frequency']]) && ($thisfile_mpeg_audio_lame['lowpass_frequency'] < 22050) && (round($thisfile_mpeg_audio_lame['lowpass_frequency'] / 1000) < round($thisfile_mpeg_audio['sample_rate'] / 2000))) {
                                $encoder_options .= ' --lowpass ' . $thisfile_mpeg_audio_lame['lowpass_frequency'];
                            }
                            break;

                        default:
                            break;
                    }
                    break;
            }
        }

        if (isset($thisfile_mpeg_audio_lame['raw']['source_sample_freq'])) {
            if (($thisfile_mpeg_audio['sample_rate'] == 44100) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 1)) {
                $encoder_options .= ' --resample 44100';
            } elseif (($thisfile_mpeg_audio['sample_rate'] == 48000) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 2)) {
                $encoder_options .= ' --resample 48000';
            } elseif ($thisfile_mpeg_audio['sample_rate'] < 44100) {
                switch ($thisfile_mpeg_audio_lame['raw']['source_sample_freq']) {
                    case 0: // <= 32000
                        // may or may not be same as source frequency - ignore
                        break;
                    case 1: // 44100
                    case 2: // 48000
                    case 3: // 48000+
                        $ExplodedOptions = explode(' ', $encoder_options, 4);
                        switch ($ExplodedOptions[0]) {
                            case '--preset':
                            case '--alt-preset':
                                switch ($ExplodedOptions[1]) {
                                    case 'fast':
                                    case 'portable':
                                    case 'medium':
                                    case 'standard':
                                    case 'extreme':
                                    case 'insane':
                                        $encoder_options .= ' --resample ' . $thisfile_mpeg_audio['sample_rate'];
                                        break;

                                    default:
                                        static $ExpectedResampledRate = array(
                                            'phon+/lw/mw-eu/sw|16000' => 16000,
                                            'mw-us|24000' => 24000, // 3.95
                                            'mw-us|32000' => 32000, // 3.93
                                            'mw-us|16000' => 16000, // 3.92
                                            'phone|16000' => 16000,
                                            'phone|11025' => 11025, // 3.94a15
                                            'radio|32000' => 32000, // 3.94a15
                                            'fm/radio|32000' => 32000, // 3.92
                                            'fm|32000' => 32000, // 3.90
                                            'voice|32000' => 32000);
                                        if (!isset($ExpectedResampledRate[$ExplodedOptions[1] . '|' . $thisfile_mpeg_audio['sample_rate']])) {
                                            $encoder_options .= ' --resample ' . $thisfile_mpeg_audio['sample_rate'];
                                        }
                                        break;
                                }
                                break;

                            case '--r3mix':
                            default:
                                $encoder_options .= ' --resample ' . $thisfile_mpeg_audio['sample_rate'];
                                break;
                        }
                        break;
                }
            }
        }
        if (empty($encoder_options) && !empty($info['audio']['bitrate']) && !empty($info['audio']['bitrate_mode'])) {
            //$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
            $encoder_options = strtoupper($info['audio']['bitrate_mode']);
        }

        return $encoder_options;
    }


    public function decodeMPEGaudioHeader($offset, &$info, $recursivesearch = true, $ScanAsCBR = false, $FastMPEGheaderScan = false)
    {
        static $MPEGaudioVersionLookup;
        static $MPEGaudioLayerLookup;
        static $MPEGaudioBitrateLookup;
        static $MPEGaudioFrequencyLookup;
        static $MPEGaudioChannelModeLookup;
        static $MPEGaudioModeExtensionLookup;
        static $MPEGaudioEmphasisLookup;
        if (empty($MPEGaudioVersionLookup)) {
            $MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
            $MPEGaudioLayerLookup = self::MPEGaudioLayerArray();
            $MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
            $MPEGaudioFrequencyLookup = self::MPEGaudioFrequencyArray();
            $MPEGaudioChannelModeLookup = self::MPEGaudioChannelModeArray();
            $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
            $MPEGaudioEmphasisLookup = self::MPEGaudioEmphasisArray();
        }

        if (fseek($this->getid3->fp, $offset, SEEK_SET) != 0) {
            $info['error'][] = 'decodeMPEGaudioHeader() failed to seek to next offset at ' . $offset;
            return false;
        }
        //$headerstring = fread($this->getid3->fp, 1441); // worst-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
        $headerstring = fread($this->getid3->fp, 226); // LAME header at offset 36 + 190 bytes of Xing/LAME data

        // MP3 audio frame structure:
        // $aa $aa $aa $aa [$bb $bb] $cc...
        // where $aa..$aa is the four-byte mpeg-audio header (below)
        // $bb $bb is the optional 2-byte CRC
        // and $cc... is the audio data

        $head4 = substr($headerstring, 0, 4);

        static $MPEGaudioHeaderDecodeCache = array();
        if (isset($MPEGaudioHeaderDecodeCache[$head4])) {
            $MPEGheaderRawArray = $MPEGaudioHeaderDecodeCache[$head4];
        } else {
            $MPEGheaderRawArray = self::MPEGaudioHeaderDecode($head4);
            $MPEGaudioHeaderDecodeCache[$head4] = $MPEGheaderRawArray;
        }

        static $MPEGaudioHeaderValidCache = array();
        if (!isset($MPEGaudioHeaderValidCache[$head4])) { // Not in cache
            //$MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, true);  // allow badly-formatted freeformat (from LAME 3.90 - 3.93.1)
            $MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, false);
        }

        // shortcut
        if (!isset($info['mpeg']['audio'])) {
            $info['mpeg']['audio'] = array();
        }
        $thisfile_mpeg_audio = & $info['mpeg']['audio'];


        if ($MPEGaudioHeaderValidCache[$head4]) {
            $thisfile_mpeg_audio['raw'] = $MPEGheaderRawArray;
        } else {
            $info['error'][] = 'Invalid MPEG audio header (' . getid3_lib::PrintHexBytes($head4) . ') at offset ' . $offset;
            return false;
        }

        if (!$FastMPEGheaderScan) {
            $thisfile_mpeg_audio['version'] = $MPEGaudioVersionLookup[$thisfile_mpeg_audio['raw']['version']];
            $thisfile_mpeg_audio['layer'] = $MPEGaudioLayerLookup[$thisfile_mpeg_audio['raw']['layer']];

            $thisfile_mpeg_audio['channelmode'] = $MPEGaudioChannelModeLookup[$thisfile_mpeg_audio['raw']['channelmode']];
            $thisfile_mpeg_audio['channels'] = (($thisfile_mpeg_audio['channelmode'] == 'mono') ? 1 : 2);
            $thisfile_mpeg_audio['sample_rate'] = $MPEGaudioFrequencyLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['raw']['sample_rate']];
            $thisfile_mpeg_audio['protection'] = !$thisfile_mpeg_audio['raw']['protection'];
            $thisfile_mpeg_audio['private'] = (bool)$thisfile_mpeg_audio['raw']['private'];
            $thisfile_mpeg_audio['modeextension'] = $MPEGaudioModeExtensionLookup[$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['modeextension']];
            $thisfile_mpeg_audio['copyright'] = (bool)$thisfile_mpeg_audio['raw']['copyright'];
            $thisfile_mpeg_audio['original'] = (bool)$thisfile_mpeg_audio['raw']['original'];
            $thisfile_mpeg_audio['emphasis'] = $MPEGaudioEmphasisLookup[$thisfile_mpeg_audio['raw']['emphasis']];

            $info['audio']['channels'] = $thisfile_mpeg_audio['channels'];
            $info['audio']['sample_rate'] = $thisfile_mpeg_audio['sample_rate'];

            if ($thisfile_mpeg_audio['protection']) {
                $thisfile_mpeg_audio['crc'] = getid3_lib::BigEndian2Int(substr($headerstring, 4, 2));
            }
        }

        if ($thisfile_mpeg_audio['raw']['bitrate'] == 15) {
            // http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
            $info['warning'][] = 'Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1';
            $thisfile_mpeg_audio['raw']['bitrate'] = 0;
        }
        $thisfile_mpeg_audio['padding'] = (bool)$thisfile_mpeg_audio['raw']['padding'];
        $thisfile_mpeg_audio['bitrate'] = $MPEGaudioBitrateLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['bitrate']];

        if (($thisfile_mpeg_audio['bitrate'] == 'free') && ($offset == $info['avdataoffset'])) {
            // only skip multiple frame check if free-format bitstream found at beginning of file
            // otherwise is quite possibly simply corrupted data
            $recursivesearch = false;
        }

        // For Layer 2 there are some combinations of bitrate and mode which are not allowed.
        if (!$FastMPEGheaderScan && ($thisfile_mpeg_audio['layer'] == '2')) {

            $info['audio']['dataformat'] = 'mp2';
            switch ($thisfile_mpeg_audio['channelmode']) {

                case 'mono':
                    if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] <= 192000)) {
                        // these are ok
                    } else {
                        $info['error'][] = $thisfile_mpeg_audio['bitrate'] . 'kbps not allowed in Layer 2, ' . $thisfile_mpeg_audio['channelmode'] . '.';
                        return false;
                    }
                    break;

                case 'stereo':
                case 'joint stereo':
                case 'dual channel':
                    if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] == 64000) || ($thisfile_mpeg_audio['bitrate'] >= 96000)) {
                        // these are ok
                    } else {
                        $info['error'][] = intval(round($thisfile_mpeg_audio['bitrate'] / 1000)) . 'kbps not allowed in Layer 2, ' . $thisfile_mpeg_audio['channelmode'] . '.';
                        return false;
                    }
                    break;

            }

        }


        if ($info['audio']['sample_rate'] > 0) {
            $thisfile_mpeg_audio['framelength'] = self::MPEGaudioFrameLength($thisfile_mpeg_audio['bitrate'], $thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['layer'], (int)$thisfile_mpeg_audio['padding'], $info['audio']['sample_rate']);
        }

        $nextframetestoffset = $offset + 1;
        if ($thisfile_mpeg_audio['bitrate'] != 'free') {

            $info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];

            if (isset($thisfile_mpeg_audio['framelength'])) {
                $nextframetestoffset = $offset + $thisfile_mpeg_audio['framelength'];
            } else {
                $info['error'][] = 'Frame at offset(' . $offset . ') is has an invalid frame length.';
                return false;
            }

        }

        $ExpectedNumberOfAudioBytes = 0;

        ////////////////////////////////////////////////////////////////////////////////////
        // Variable-bitrate headers

        if (substr($headerstring, 4 + 32, 4) == 'VBRI') {
            // Fraunhofer VBR header is hardcoded 'VBRI' at offset 0x24 (36)
            // specs taken from http://minnie.tuhs.org/pipermail/mp3encoder/2001-January/001800.html

            $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
            $thisfile_mpeg_audio['VBR_method'] = 'Fraunhofer';
            $info['audio']['codec'] = 'Fraunhofer';

            $SideInfoData = substr($headerstring, 4 + 2, 32);

            $FraunhoferVBROffset = 36;

            $thisfile_mpeg_audio['VBR_encoder_version'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 4, 2)); // VbriVersion
            $thisfile_mpeg_audio['VBR_encoder_delay'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 6, 2)); // VbriDelay
            $thisfile_mpeg_audio['VBR_quality'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 8, 2)); // VbriQuality
            $thisfile_mpeg_audio['VBR_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 10, 4)); // VbriStreamBytes
            $thisfile_mpeg_audio['VBR_frames'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 14, 4)); // VbriStreamFrames
            $thisfile_mpeg_audio['VBR_seek_offsets'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 18, 2)); // VbriTableSize
            $thisfile_mpeg_audio['VBR_seek_scale'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 20, 2)); // VbriTableScale
            $thisfile_mpeg_audio['VBR_entry_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 22, 2)); // VbriEntryBytes
            $thisfile_mpeg_audio['VBR_entry_frames'] = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 24, 2)); // VbriEntryFrames

            $ExpectedNumberOfAudioBytes = $thisfile_mpeg_audio['VBR_bytes'];

            $previousbyteoffset = $offset;
            for ($i = 0; $i < $thisfile_mpeg_audio['VBR_seek_offsets']; $i++) {
                $Fraunhofer_OffsetN = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset, $thisfile_mpeg_audio['VBR_entry_bytes']));
                $FraunhoferVBROffset += $thisfile_mpeg_audio['VBR_entry_bytes'];
                $thisfile_mpeg_audio['VBR_offsets_relative'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']);
                $thisfile_mpeg_audio['VBR_offsets_absolute'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']) + $previousbyteoffset;
                $previousbyteoffset += $Fraunhofer_OffsetN;
            }


        } else {

            // Xing VBR header is hardcoded 'Xing' at a offset 0x0D (13), 0x15 (21) or 0x24 (36)
            // depending on MPEG layer and number of channels

            $VBRidOffset = self::XingVBRidOffset($thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['channelmode']);
            $SideInfoData = substr($headerstring, 4 + 2, $VBRidOffset - 4);

            if ((substr($headerstring, $VBRidOffset, strlen('Xing')) == 'Xing') || (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Info')) {
                // 'Xing' is traditional Xing VBR frame
                // 'Info' is LAME-encoded CBR (This was done to avoid CBR files to be recognized as traditional Xing VBR files by some decoders.)
                // 'Info' *can* legally be used to specify a VBR file as well, however.

                // http://www.multiweb.cz/twoinches/MP3inside.htm
                //00..03 = "Xing" or "Info"
                //04..07 = Flags:
                //  0x01  Frames Flag     set if value for number of frames in file is stored
                //  0x02  Bytes Flag      set if value for filesize in bytes is stored
                //  0x04  TOC Flag        set if values for TOC are stored
                //  0x08  VBR Scale Flag  set if values for VBR scale is stored
                //08..11  Frames: Number of frames in file (including the first Xing/Info one)
                //12..15  Bytes:  File length in Bytes
                //16..115  TOC (Table of Contents):
                //  Contains of 100 indexes (one Byte length) for easier lookup in file. Approximately solves problem with moving inside file.
                //  Each Byte has a value according this formula:
                //  (TOC[i] / 256) * fileLenInBytes
                //  So if song lasts eg. 240 sec. and you want to jump to 60. sec. (and file is 5 000 000 Bytes length) you can use:
                //  TOC[(60/240)*100] = TOC[25]
                //  and corresponding Byte in file is then approximately at:
                //  (TOC[25]/256) * 5000000
                //116..119  VBR Scale


                // should be safe to leave this at 'vbr' and let it be overriden to 'cbr' if a CBR preset/mode is used by LAME
//				if (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Xing') {
                $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
                $thisfile_mpeg_audio['VBR_method'] = 'Xing';
//				} else {
//					$ScanAsCBR = true;
//					$thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
//				}

                $thisfile_mpeg_audio['xing_flags_raw'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 4, 4));

                $thisfile_mpeg_audio['xing_flags']['frames'] = (bool)($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000001);
                $thisfile_mpeg_audio['xing_flags']['bytes'] = (bool)($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000002);
                $thisfile_mpeg_audio['xing_flags']['toc'] = (bool)($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000004);
                $thisfile_mpeg_audio['xing_flags']['vbr_scale'] = (bool)($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000008);

                if ($thisfile_mpeg_audio['xing_flags']['frames']) {
                    $thisfile_mpeg_audio['VBR_frames'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 8, 4));
                    //$thisfile_mpeg_audio['VBR_frames']--; // don't count header Xing/Info frame
                }
                if ($thisfile_mpeg_audio['xing_flags']['bytes']) {
                    $thisfile_mpeg_audio['VBR_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 12, 4));
                }

                //if (($thisfile_mpeg_audio['bitrate'] == 'free') && !empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
                if (!empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {

                    $framelengthfloat = $thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames'];

                    if ($thisfile_mpeg_audio['layer'] == '1') {
                        // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
                        //$info['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
                        $info['audio']['bitrate'] = ($framelengthfloat / 4) * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 12;
                    } else {
                        // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
                        //$info['audio']['bitrate'] = (($framelengthfloat - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
                        $info['audio']['bitrate'] = $framelengthfloat * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 144;
                    }
                    $thisfile_mpeg_audio['framelength'] = floor($framelengthfloat);
                }

                if ($thisfile_mpeg_audio['xing_flags']['toc']) {
                    $LAMEtocData = substr($headerstring, $VBRidOffset + 16, 100);
                    for ($i = 0; $i < 100; $i++) {
                        $thisfile_mpeg_audio['toc'][$i] = ord($LAMEtocData{$i});
                    }
                }
                if ($thisfile_mpeg_audio['xing_flags']['vbr_scale']) {
                    $thisfile_mpeg_audio['VBR_scale'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 116, 4));
                }


                // http://gabriel.mp3-tech.org/mp3infotag.html
                if (substr($headerstring, $VBRidOffset + 120, 4) == 'LAME') {

                    // shortcut
                    $thisfile_mpeg_audio['LAME'] = array();
                    $thisfile_mpeg_audio_lame = & $thisfile_mpeg_audio['LAME'];


                    $thisfile_mpeg_audio_lame['long_version'] = substr($headerstring, $VBRidOffset + 120, 20);
                    $thisfile_mpeg_audio_lame['short_version'] = substr($thisfile_mpeg_audio_lame['long_version'], 0, 9);

                    if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.90') {

                        // extra 11 chars are not part of version string when LAMEtag present
                        unset($thisfile_mpeg_audio_lame['long_version']);

                        // It the LAME tag was only introduced in LAME v3.90
                        // http://www.hydrogenaudio.org/?act=ST&f=15&t=9933

                        // Offsets of various bytes in http://gabriel.mp3-tech.org/mp3infotag.html
                        // are assuming a 'Xing' identifier offset of 0x24, which is the case for
                        // MPEG-1 non-mono, but not for other combinations
                        $LAMEtagOffsetContant = $VBRidOffset - 0x24;

                        // shortcuts
                        $thisfile_mpeg_audio_lame['RGAD'] = array('track' => array(), 'album' => array());
                        $thisfile_mpeg_audio_lame_RGAD = & $thisfile_mpeg_audio_lame['RGAD'];
                        $thisfile_mpeg_audio_lame_RGAD_track = & $thisfile_mpeg_audio_lame_RGAD['track'];
                        $thisfile_mpeg_audio_lame_RGAD_album = & $thisfile_mpeg_audio_lame_RGAD['album'];
                        $thisfile_mpeg_audio_lame['raw'] = array();
                        $thisfile_mpeg_audio_lame_raw = & $thisfile_mpeg_audio_lame['raw'];

                        // byte $9B  VBR Quality
                        // This field is there to indicate a quality level, although the scale was not precised in the original Xing specifications.
                        // Actually overwrites original Xing bytes
                        unset($thisfile_mpeg_audio['VBR_scale']);
                        $thisfile_mpeg_audio_lame['vbr_quality'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0x9B, 1));

                        // bytes $9C-$A4  Encoder short VersionString
                        $thisfile_mpeg_audio_lame['short_version'] = substr($headerstring, $LAMEtagOffsetContant + 0x9C, 9);

                        // byte $A5  Info Tag revision + VBR method
                        $LAMEtagRevisionVBRmethod = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA5, 1));

                        $thisfile_mpeg_audio_lame['tag_revision'] = ($LAMEtagRevisionVBRmethod & 0xF0) >> 4;
                        $thisfile_mpeg_audio_lame_raw['vbr_method'] = $LAMEtagRevisionVBRmethod & 0x0F;
                        $thisfile_mpeg_audio_lame['vbr_method'] = self::LAMEvbrMethodLookup($thisfile_mpeg_audio_lame_raw['vbr_method']);
                        $thisfile_mpeg_audio['bitrate_mode'] = substr($thisfile_mpeg_audio_lame['vbr_method'], 0, 3); // usually either 'cbr' or 'vbr', but truncates 'vbr-old / vbr-rh' to 'vbr'

                        // byte $A6  Lowpass filter value
                        $thisfile_mpeg_audio_lame['lowpass_frequency'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA6, 1)) * 100;

                        // bytes $A7-$AE  Replay Gain
                        // http://privatewww.essex.ac.uk/~djmrob/replaygain/rg_data_format.html
                        // bytes $A7-$AA : 32 bit floating point "Peak signal amplitude"
                        if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.94b') {
                            // LAME 3.94a16 and later - 9.23 fixed point
                            // ie 0x0059E2EE / (2^23) = 5890798 / 8388608 = 0.7022378444671630859375
                            $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = (float)((getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4))) / 8388608);
                        } else {
                            // LAME 3.94a15 and earlier - 32-bit floating point
                            // Actually 3.94a16 will fall in here too and be WRONG, but is hard to detect 3.94a16 vs 3.94a15
                            $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = getid3_lib::LittleEndian2Float(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4));
                        }
                        if ($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] == 0) {
                            unset($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
                        } else {
                            $thisfile_mpeg_audio_lame_RGAD['peak_db'] = getid3_lib::RGADamplitude2dB($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
                        }

                        $thisfile_mpeg_audio_lame_raw['RGAD_track'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAB, 2));
                        $thisfile_mpeg_audio_lame_raw['RGAD_album'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAD, 2));


                        if ($thisfile_mpeg_audio_lame_raw['RGAD_track'] != 0) {

                            $thisfile_mpeg_audio_lame_RGAD_track['raw']['name'] = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0xE000) >> 13;
                            $thisfile_mpeg_audio_lame_RGAD_track['raw']['originator'] = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x1C00) >> 10;
                            $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit'] = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x0200) >> 9;
                            $thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x01FF;
                            $thisfile_mpeg_audio_lame_RGAD_track['name'] = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['name']);
                            $thisfile_mpeg_audio_lame_RGAD_track['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']);
                            $thisfile_mpeg_audio_lame_RGAD_track['gain_db'] = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']);

                            if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
                                $info['replay_gain']['track']['peak'] = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
                            }
                            $info['replay_gain']['track']['originator'] = $thisfile_mpeg_audio_lame_RGAD_track['originator'];
                            $info['replay_gain']['track']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_track['gain_db'];
                        } else {
                            unset($thisfile_mpeg_audio_lame_RGAD['track']);
                        }
                        if ($thisfile_mpeg_audio_lame_raw['RGAD_album'] != 0) {

                            $thisfile_mpeg_audio_lame_RGAD_album['raw']['name'] = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0xE000) >> 13;
                            $thisfile_mpeg_audio_lame_RGAD_album['raw']['originator'] = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x1C00) >> 10;
                            $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit'] = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x0200) >> 9;
                            $thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x01FF;
                            $thisfile_mpeg_audio_lame_RGAD_album['name'] = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['name']);
                            $thisfile_mpeg_audio_lame_RGAD_album['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']);
                            $thisfile_mpeg_audio_lame_RGAD_album['gain_db'] = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']);

                            if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
                                $info['replay_gain']['album']['peak'] = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
                            }
                            $info['replay_gain']['album']['originator'] = $thisfile_mpeg_audio_lame_RGAD_album['originator'];
                            $info['replay_gain']['album']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_album['gain_db'];
                        } else {
                            unset($thisfile_mpeg_audio_lame_RGAD['album']);
                        }
                        if (empty($thisfile_mpeg_audio_lame_RGAD)) {
                            unset($thisfile_mpeg_audio_lame['RGAD']);
                        }


                        // byte $AF  Encoding flags + ATH Type
                        $EncodingFlagsATHtype = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAF, 1));
                        $thisfile_mpeg_audio_lame['encoding_flags']['nspsytune'] = (bool)($EncodingFlagsATHtype & 0x10);
                        $thisfile_mpeg_audio_lame['encoding_flags']['nssafejoint'] = (bool)($EncodingFlagsATHtype & 0x20);
                        $thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'] = (bool)($EncodingFlagsATHtype & 0x40);
                        $thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev'] = (bool)($EncodingFlagsATHtype & 0x80);
                        $thisfile_mpeg_audio_lame['ath_type'] = $EncodingFlagsATHtype & 0x0F;

                        // byte $B0  if ABR {specified bitrate} else {minimal bitrate}
                        $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB0, 1));
                        if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 2) { // Average BitRate (ABR)
                            $thisfile_mpeg_audio_lame['bitrate_abr'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
                        } elseif ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) { // Constant BitRate (CBR)
                            // ignore
                        } elseif ($thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] > 0) { // Variable BitRate (VBR) - minimum bitrate
                            $thisfile_mpeg_audio_lame['bitrate_min'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
                        }

                        // bytes $B1-$B3  Encoder delays
                        $EncoderDelays = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB1, 3));
                        $thisfile_mpeg_audio_lame['encoder_delay'] = ($EncoderDelays & 0xFFF000) >> 12;
                        $thisfile_mpeg_audio_lame['end_padding'] = $EncoderDelays & 0x000FFF;

                        // byte $B4  Misc
                        $MiscByte = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB4, 1));
                        $thisfile_mpeg_audio_lame_raw['noise_shaping'] = ($MiscByte & 0x03);
                        $thisfile_mpeg_audio_lame_raw['stereo_mode'] = ($MiscByte & 0x1C) >> 2;
                        $thisfile_mpeg_audio_lame_raw['not_optimal_quality'] = ($MiscByte & 0x20) >> 5;
                        $thisfile_mpeg_audio_lame_raw['source_sample_freq'] = ($MiscByte & 0xC0) >> 6;
                        $thisfile_mpeg_audio_lame['noise_shaping'] = $thisfile_mpeg_audio_lame_raw['noise_shaping'];
                        $thisfile_mpeg_audio_lame['stereo_mode'] = self::LAMEmiscStereoModeLookup($thisfile_mpeg_audio_lame_raw['stereo_mode']);
                        $thisfile_mpeg_audio_lame['not_optimal_quality'] = (bool)$thisfile_mpeg_audio_lame_raw['not_optimal_quality'];
                        $thisfile_mpeg_audio_lame['source_sample_freq'] = self::LAMEmiscSourceSampleFrequencyLookup($thisfile_mpeg_audio_lame_raw['source_sample_freq']);

                        // byte $B5  MP3 Gain
                        $thisfile_mpeg_audio_lame_raw['mp3_gain'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB5, 1), false, true);
                        $thisfile_mpeg_audio_lame['mp3_gain_db'] = (getid3_lib::RGADamplitude2dB(2) / 4) * $thisfile_mpeg_audio_lame_raw['mp3_gain'];
                        $thisfile_mpeg_audio_lame['mp3_gain_factor'] = pow(2, ($thisfile_mpeg_audio_lame['mp3_gain_db'] / 6));

                        // bytes $B6-$B7  Preset and surround info
                        $PresetSurroundBytes = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB6, 2));
                        // Reserved                                                    = ($PresetSurroundBytes & 0xC000);
                        $thisfile_mpeg_audio_lame_raw['surround_info'] = ($PresetSurroundBytes & 0x3800);
                        $thisfile_mpeg_audio_lame['surround_info'] = self::LAMEsurroundInfoLookup($thisfile_mpeg_audio_lame_raw['surround_info']);
                        $thisfile_mpeg_audio_lame['preset_used_id'] = ($PresetSurroundBytes & 0x07FF);
                        $thisfile_mpeg_audio_lame['preset_used'] = self::LAMEpresetUsedLookup($thisfile_mpeg_audio_lame);
                        if (!empty($thisfile_mpeg_audio_lame['preset_used_id']) && empty($thisfile_mpeg_audio_lame['preset_used'])) {
                            $info['warning'][] = 'Unknown LAME preset used (' . $thisfile_mpeg_audio_lame['preset_used_id'] . ') - please report to info@getid3.org';
                        }
                        if (($thisfile_mpeg_audio_lame['short_version'] == 'LAME3.90.') && !empty($thisfile_mpeg_audio_lame['preset_used_id'])) {
                            // this may change if 3.90.4 ever comes out
                            $thisfile_mpeg_audio_lame['short_version'] = 'LAME3.90.3';
                        }

                        // bytes $B8-$BB  MusicLength
                        $thisfile_mpeg_audio_lame['audio_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB8, 4));
                        $ExpectedNumberOfAudioBytes = (($thisfile_mpeg_audio_lame['audio_bytes'] > 0) ? $thisfile_mpeg_audio_lame['audio_bytes'] : $thisfile_mpeg_audio['VBR_bytes']);

                        // bytes $BC-$BD  MusicCRC
                        $thisfile_mpeg_audio_lame['music_crc'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBC, 2));

                        // bytes $BE-$BF  CRC-16 of Info Tag
                        $thisfile_mpeg_audio_lame['lame_tag_crc'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBE, 2));


                        // LAME CBR
                        if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) {

                            $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
                            $thisfile_mpeg_audio['bitrate'] = self::ClosestStandardMP3Bitrate($thisfile_mpeg_audio['bitrate']);
                            $info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
                            //if (empty($thisfile_mpeg_audio['bitrate']) || (!empty($thisfile_mpeg_audio_lame['bitrate_min']) && ($thisfile_mpeg_audio_lame['bitrate_min'] != 255))) {
                            //	$thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio_lame['bitrate_min'];
                            //}

                        }

                    }
                }

            } else {

                // not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
                $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
                if ($recursivesearch) {
                    $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
                    if ($this->RecursiveFrameScanning($offset, $nextframetestoffset, true)) {
                        $recursivesearch = false;
                        $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
                    }
                    if ($thisfile_mpeg_audio['bitrate_mode'] == 'vbr') {
                        $info['warning'][] = 'VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.';
                    }
                }

            }

        }

        if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($info['avdataend'] - $info['avdataoffset']))) {
            if ($ExpectedNumberOfAudioBytes > ($info['avdataend'] - $info['avdataoffset'])) {
                if (isset($info['fileformat']) && ($info['fileformat'] == 'riff')) {
                    // ignore, audio data is broken into chunks so will always be data "missing"
                } elseif (($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])) == 1) {
                    $info['warning'][] = 'Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)';
                } else {
                    $info['warning'][] = 'Probable truncated file: expecting ' . $ExpectedNumberOfAudioBytes . ' bytes of audio data, only found ' . ($info['avdataend'] - $info['avdataoffset']) . ' (short by ' . ($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])) . ' bytes)';
                }
            } else {
                if ((($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes) == 1) {
                    //	$prenullbytefileoffset = ftell($this->getid3->fp);
                    //	fseek($this->getid3->fp, $info['avdataend'], SEEK_SET);
                    //	$PossibleNullByte = fread($this->getid3->fp, 1);
                    //	fseek($this->getid3->fp, $prenullbytefileoffset, SEEK_SET);
                    //	if ($PossibleNullByte === "\x00") {
                    $info['avdataend']--;
                    //		$info['warning'][] = 'Extra null byte at end of MP3 data assumed to be RIFF padding and therefore ignored';
                    //	} else {
                    //		$info['warning'][] = 'Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)';
                    //	}
                } else {
                    $info['warning'][] = 'Too much data in file: expecting ' . $ExpectedNumberOfAudioBytes . ' bytes of audio data, found ' . ($info['avdataend'] - $info['avdataoffset']) . ' (' . (($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes) . ' bytes too many)';
                }
            }
        }

        if (($thisfile_mpeg_audio['bitrate'] == 'free') && empty($info['audio']['bitrate'])) {
            if (($offset == $info['avdataoffset']) && empty($thisfile_mpeg_audio['VBR_frames'])) {
                $framebytelength = $this->FreeFormatFrameLength($offset, true);
                if ($framebytelength > 0) {
                    $thisfile_mpeg_audio['framelength'] = $framebytelength;
                    if ($thisfile_mpeg_audio['layer'] == '1') {
                        // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
                        $info['audio']['bitrate'] = ((($framebytelength / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
                    } else {
                        // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
                        $info['audio']['bitrate'] = (($framebytelength - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
                    }
                } else {
                    $info['error'][] = 'Error calculating frame length of free-format MP3 without Xing/LAME header';
                }
            }
        }

        if (isset($thisfile_mpeg_audio['VBR_frames']) ? $thisfile_mpeg_audio['VBR_frames'] : '') {
            switch ($thisfile_mpeg_audio['bitrate_mode']) {
                case 'vbr':
                case 'abr':
                    $bytes_per_frame = 1152;
                    if (($thisfile_mpeg_audio['version'] == '1') && ($thisfile_mpeg_audio['layer'] == 1)) {
                        $bytes_per_frame = 384;
                    } elseif ((($thisfile_mpeg_audio['version'] == '2') || ($thisfile_mpeg_audio['version'] == '2.5')) && ($thisfile_mpeg_audio['layer'] == 3)) {
                        $bytes_per_frame = 576;
                    }
                    $thisfile_mpeg_audio['VBR_bitrate'] = (isset($thisfile_mpeg_audio['VBR_bytes']) ? (($thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($info['audio']['sample_rate'] / $bytes_per_frame) : 0);
                    if ($thisfile_mpeg_audio['VBR_bitrate'] > 0) {
                        $info['audio']['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate'];
                        $thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate']; // to avoid confusion
                    }
                    break;
            }
        }

        // End variable-bitrate headers
        ////////////////////////////////////////////////////////////////////////////////////

        if ($recursivesearch) {

            if (!$this->RecursiveFrameScanning($offset, $nextframetestoffset, $ScanAsCBR)) {
                return false;
            }

        }


        //if (false) {
        //    // experimental side info parsing section - not returning anything useful yet
        //
        //    $SideInfoBitstream = getid3_lib::BigEndian2Bin($SideInfoData);
        //    $SideInfoOffset = 0;
        //
        //    if ($thisfile_mpeg_audio['version'] == '1') {
        //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
        //            // MPEG-1 (mono)
        //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
        //            $SideInfoOffset += 9;
        //            $SideInfoOffset += 5;
        //        } else {
        //            // MPEG-1 (stereo, joint-stereo, dual-channel)
        //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
        //            $SideInfoOffset += 9;
        //            $SideInfoOffset += 3;
        //        }
        //    } else { // 2 or 2.5
        //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
        //            // MPEG-2, MPEG-2.5 (mono)
        //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
        //            $SideInfoOffset += 8;
        //            $SideInfoOffset += 1;
        //        } else {
        //            // MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
        //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
        //            $SideInfoOffset += 8;
        //            $SideInfoOffset += 2;
        //        }
        //    }
        //
        //    if ($thisfile_mpeg_audio['version'] == '1') {
        //        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
        //            for ($scfsi_band = 0; $scfsi_band < 4; $scfsi_band++) {
        //                $thisfile_mpeg_audio['scfsi'][$channel][$scfsi_band] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //                $SideInfoOffset += 2;
        //            }
        //        }
        //    }
        //    for ($granule = 0; $granule < (($thisfile_mpeg_audio['version'] == '1') ? 2 : 1); $granule++) {
        //        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
        //            $thisfile_mpeg_audio['part2_3_length'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 12);
        //            $SideInfoOffset += 12;
        //            $thisfile_mpeg_audio['big_values'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
        //            $SideInfoOffset += 9;
        //            $thisfile_mpeg_audio['global_gain'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 8);
        //            $SideInfoOffset += 8;
        //            if ($thisfile_mpeg_audio['version'] == '1') {
        //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
        //                $SideInfoOffset += 4;
        //            } else {
        //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
        //                $SideInfoOffset += 9;
        //            }
        //            $thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //            $SideInfoOffset += 1;
        //
        //            if ($thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] == '1') {
        //
        //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 2);
        //                $SideInfoOffset += 2;
        //                $thisfile_mpeg_audio['mixed_block_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //                $SideInfoOffset += 1;
        //
        //                for ($region = 0; $region < 2; $region++) {
        //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
        //                    $SideInfoOffset += 5;
        //                }
        //                $thisfile_mpeg_audio['table_select'][$granule][$channel][2] = 0;
        //
        //                for ($window = 0; $window < 3; $window++) {
        //                    $thisfile_mpeg_audio['subblock_gain'][$granule][$channel][$window] = substr($SideInfoBitstream, $SideInfoOffset, 3);
        //                    $SideInfoOffset += 3;
        //                }
        //
        //            } else {
        //
        //                for ($region = 0; $region < 3; $region++) {
        //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
        //                    $SideInfoOffset += 5;
        //                }
        //
        //                $thisfile_mpeg_audio['region0_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
        //                $SideInfoOffset += 4;
        //                $thisfile_mpeg_audio['region1_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 3);
        //                $SideInfoOffset += 3;
        //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = 0;
        //            }
        //
        //            if ($thisfile_mpeg_audio['version'] == '1') {
        //                $thisfile_mpeg_audio['preflag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //                $SideInfoOffset += 1;
        //            }
        //            $thisfile_mpeg_audio['scalefac_scale'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //            $SideInfoOffset += 1;
        //            $thisfile_mpeg_audio['count1table_select'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
        //            $SideInfoOffset += 1;
        //        }
        //    }
        //}

        return true;
    }

    public function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR)
    {
        $info = & $this->getid3->info;
        $firstframetestarray = array('error' => '', 'warning' => '', 'avdataend' => $info['avdataend'], 'avdataoffset' => $info['avdataoffset']);
        $this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);

        for ($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i++) {
            // check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
            if (($nextframetestoffset + 4) >= $info['avdataend']) {
                // end of file
                return true;
            }

            $nextframetestarray = array('error' => '', 'warning' => '', 'avdataend' => $info['avdataend'], 'avdataoffset' => $info['avdataoffset']);
            if ($this->decodeMPEGaudioHeader($nextframetestoffset, $nextframetestarray, false)) {
                if ($ScanAsCBR) {
                    // force CBR mode, used for trying to pick out invalid audio streams with valid(?) VBR headers, or VBR streams with no VBR header
                    if (!isset($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
                        return false;
                    }
                }


                // next frame is OK, get ready to check the one after that
                if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
                    $nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
                } else {
                    $info['error'][] = 'Frame at offset (' . $offset . ') is has an invalid frame length.';
                    return false;
                }

            } elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {

                // it's not the end of the file, but there's not enough data left for another frame, so assume it's garbage/padding and return OK
                return true;

            } else {

                // next frame is not valid, note the error and fail, so scanning can contiue for a valid frame sequence
                $info['warning'][] = 'Frame at offset (' . $offset . ') is valid, but the next one at (' . $nextframetestoffset . ') is not.';

                return false;
            }
        }
        return true;
    }

    public function FreeFormatFrameLength($offset, $deepscan = false)
    {
        $info = & $this->getid3->info;

        fseek($this->getid3->fp, $offset, SEEK_SET);
        $MPEGaudioData = fread($this->getid3->fp, 32768);

        $SyncPattern1 = substr($MPEGaudioData, 0, 4);
        // may be different pattern due to padding
        $SyncPattern2 = $SyncPattern1{0} . $SyncPattern1{1} . chr(ord($SyncPattern1{2}) | 0x02) . $SyncPattern1{3};
        if ($SyncPattern2 === $SyncPattern1) {
            $SyncPattern2 = $SyncPattern1{0} . $SyncPattern1{1} . chr(ord($SyncPattern1{2}) & 0xFD) . $SyncPattern1{3};
        }

        $framelength = false;
        $framelength1 = strpos($MPEGaudioData, $SyncPattern1, 4);
        $framelength2 = strpos($MPEGaudioData, $SyncPattern2, 4);
        if ($framelength1 > 4) {
            $framelength = $framelength1;
        }
        if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
            $framelength = $framelength2;
        }
        if (!$framelength) {

            // LAME 3.88 has a different value for modeextension on the first frame vs the rest
            $framelength1 = strpos($MPEGaudioData, substr($SyncPattern1, 0, 3), 4);
            $framelength2 = strpos($MPEGaudioData, substr($SyncPattern2, 0, 3), 4);

            if ($framelength1 > 4) {
                $framelength = $framelength1;
            }
            if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
                $framelength = $framelength2;
            }
            if (!$framelength) {
                $info['error'][] = 'Cannot find next free-format synch pattern (' . getid3_lib::PrintHexBytes($SyncPattern1) . ' or ' . getid3_lib::PrintHexBytes($SyncPattern2) . ') after offset ' . $offset;
                return false;
            } else {
                $info['warning'][] = 'ModeExtension varies between first frame and other frames (known free-format issue in LAME 3.88)';
                $info['audio']['codec'] = 'LAME';
                $info['audio']['encoder'] = 'LAME3.88';
                $SyncPattern1 = substr($SyncPattern1, 0, 3);
                $SyncPattern2 = substr($SyncPattern2, 0, 3);
            }
        }

        if ($deepscan) {

            $ActualFrameLengthValues = array();
            $nextoffset = $offset + $framelength;
            while ($nextoffset < ($info['avdataend'] - 6)) {
                fseek($this->getid3->fp, $nextoffset - 1, SEEK_SET);
                $NextSyncPattern = fread($this->getid3->fp, 6);
                if ((substr($NextSyncPattern, 1, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 1, strlen($SyncPattern2)) == $SyncPattern2)) {
                    // good - found where expected
                    $ActualFrameLengthValues[] = $framelength;
                } elseif ((substr($NextSyncPattern, 0, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 0, strlen($SyncPattern2)) == $SyncPattern2)) {
                    // ok - found one byte earlier than expected (last frame wasn't padded, first frame was)
                    $ActualFrameLengthValues[] = ($framelength - 1);
                    $nextoffset--;
                } elseif ((substr($NextSyncPattern, 2, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 2, strlen($SyncPattern2)) == $SyncPattern2)) {
                    // ok - found one byte later than expected (last frame was padded, first frame wasn't)
                    $ActualFrameLengthValues[] = ($framelength + 1);
                    $nextoffset++;
                } else {
                    $info['error'][] = 'Did not find expected free-format sync pattern at offset ' . $nextoffset;
                    return false;
                }
                $nextoffset += $framelength;
            }
            if (count($ActualFrameLengthValues) > 0) {
                $framelength = intval(round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues)));
            }
        }
        return $framelength;
    }

    public function getOnlyMPEGaudioInfoBruteForce()
    {
        $MPEGaudioHeaderDecodeCache = array();
        $MPEGaudioHeaderValidCache = array();
        $MPEGaudioHeaderLengthCache = array();
        $MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
        $MPEGaudioLayerLookup = self::MPEGaudioLayerArray();
        $MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
        $MPEGaudioFrequencyLookup = self::MPEGaudioFrequencyArray();
        $MPEGaudioChannelModeLookup = self::MPEGaudioChannelModeArray();
        $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
        $MPEGaudioEmphasisLookup = self::MPEGaudioEmphasisArray();
        $LongMPEGversionLookup = array();
        $LongMPEGlayerLookup = array();
        $LongMPEGbitrateLookup = array();
        $LongMPEGpaddingLookup = array();
        $LongMPEGfrequencyLookup = array();
        $Distribution['bitrate'] = array();
        $Distribution['frequency'] = array();
        $Distribution['layer'] = array();
        $Distribution['version'] = array();
        $Distribution['padding'] = array();

        $info = & $this->getid3->info;
        fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);

        $max_frames_scan = 5000;
        $frames_scanned = 0;

        $previousvalidframe = $info['avdataoffset'];
        while (ftell($this->getid3->fp) < $info['avdataend']) {
            set_time_limit(30);
            $head4 = fread($this->getid3->fp, 4);
            if (strlen($head4) < 4) {
                break;
            }
            if ($head4{0} != "\xFF") {
                for ($i = 1; $i < 4; $i++) {
                    if ($head4{$i} == "\xFF") {
                        fseek($this->getid3->fp, $i - 4, SEEK_CUR);
                        continue 2;
                    }
                }
                continue;
            }
            if (!isset($MPEGaudioHeaderDecodeCache[$head4])) {
                $MPEGaudioHeaderDecodeCache[$head4] = self::MPEGaudioHeaderDecode($head4);
            }
            if (!isset($MPEGaudioHeaderValidCache[$head4])) {
                $MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$head4], false, false);
            }
            if ($MPEGaudioHeaderValidCache[$head4]) {

                if (!isset($MPEGaudioHeaderLengthCache[$head4])) {
                    $LongMPEGversionLookup[$head4] = $MPEGaudioVersionLookup[$MPEGaudioHeaderDecodeCache[$head4]['version']];
                    $LongMPEGlayerLookup[$head4] = $MPEGaudioLayerLookup[$MPEGaudioHeaderDecodeCache[$head4]['layer']];
                    $LongMPEGbitrateLookup[$head4] = $MPEGaudioBitrateLookup[$LongMPEGversionLookup[$head4]][$LongMPEGlayerLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['bitrate']];
                    $LongMPEGpaddingLookup[$head4] = (bool)$MPEGaudioHeaderDecodeCache[$head4]['padding'];
                    $LongMPEGfrequencyLookup[$head4] = $MPEGaudioFrequencyLookup[$LongMPEGversionLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['sample_rate']];
                    $MPEGaudioHeaderLengthCache[$head4] = self::MPEGaudioFrameLength(
                        $LongMPEGbitrateLookup[$head4],
                        $LongMPEGversionLookup[$head4],
                        $LongMPEGlayerLookup[$head4],
                        $LongMPEGpaddingLookup[$head4],
                        $LongMPEGfrequencyLookup[$head4]);
                }
                if ($MPEGaudioHeaderLengthCache[$head4] > 4) {
                    $WhereWeWere = ftell($this->getid3->fp);
                    fseek($this->getid3->fp, $MPEGaudioHeaderLengthCache[$head4] - 4, SEEK_CUR);
                    $next4 = fread($this->getid3->fp, 4);
                    if ($next4{0} == "\xFF") {
                        if (!isset($MPEGaudioHeaderDecodeCache[$next4])) {
                            $MPEGaudioHeaderDecodeCache[$next4] = self::MPEGaudioHeaderDecode($next4);
                        }
                        if (!isset($MPEGaudioHeaderValidCache[$next4])) {
                            $MPEGaudioHeaderValidCache[$next4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$next4], false, false);
                        }
                        if ($MPEGaudioHeaderValidCache[$next4]) {
                            fseek($this->getid3->fp, -4, SEEK_CUR);

                            getid3_lib::safe_inc($Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]]);
                            getid3_lib::safe_inc($Distribution['layer'][$LongMPEGlayerLookup[$head4]]);
                            getid3_lib::safe_inc($Distribution['version'][$LongMPEGversionLookup[$head4]]);
                            getid3_lib::safe_inc($Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])]);
                            getid3_lib::safe_inc($Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]]);
                            if ($max_frames_scan && (++$frames_scanned >= $max_frames_scan)) {
                                $pct_data_scanned = (ftell($this->getid3->fp) - $info['avdataoffset']) / ($info['avdataend'] - $info['avdataoffset']);
                                $info['warning'][] = 'too many MPEG audio frames to scan, only scanned first ' . $max_frames_scan . ' frames (' . number_format($pct_data_scanned * 100, 1) . '% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';
                                foreach ($Distribution as $key1 => $value1) {
                                    foreach ($value1 as $key2 => $value2) {
                                        $Distribution[$key1][$key2] = round($value2 / $pct_data_scanned);
                                    }
                                }
                                break;
                            }
                            continue;
                        }
                    }
                    unset($next4);
                    fseek($this->getid3->fp, $WhereWeWere - 3, SEEK_SET);
                }

            }
        }
        foreach ($Distribution as $key => $value) {
            ksort($Distribution[$key], SORT_NUMERIC);
        }
        ksort($Distribution['version'], SORT_STRING);
        $info['mpeg']['audio']['bitrate_distribution'] = $Distribution['bitrate'];
        $info['mpeg']['audio']['frequency_distribution'] = $Distribution['frequency'];
        $info['mpeg']['audio']['layer_distribution'] = $Distribution['layer'];
        $info['mpeg']['audio']['version_distribution'] = $Distribution['version'];
        $info['mpeg']['audio']['padding_distribution'] = $Distribution['padding'];
        if (count($Distribution['version']) > 1) {
            $info['error'][] = 'Corrupt file - more than one MPEG version detected';
        }
        if (count($Distribution['layer']) > 1) {
            $info['error'][] = 'Corrupt file - more than one MPEG layer detected';
        }
        if (count($Distribution['frequency']) > 1) {
            $info['error'][] = 'Corrupt file - more than one MPEG sample rate detected';
        }


        $bittotal = 0;
        foreach ($Distribution['bitrate'] as $bitratevalue => $bitratecount) {
            if ($bitratevalue != 'free') {
                $bittotal += ($bitratevalue * $bitratecount);
            }
        }
        $info['mpeg']['audio']['frame_count'] = array_sum($Distribution['bitrate']);
        if ($info['mpeg']['audio']['frame_count'] == 0) {
            $info['error'][] = 'no MPEG audio frames found';
            return false;
        }
        $info['mpeg']['audio']['bitrate'] = ($bittotal / $info['mpeg']['audio']['frame_count']);
        $info['mpeg']['audio']['bitrate_mode'] = ((count($Distribution['bitrate']) > 0) ? 'vbr' : 'cbr');
        $info['mpeg']['audio']['sample_rate'] = getid3_lib::array_max($Distribution['frequency'], true);

        $info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];
        $info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
        $info['audio']['sample_rate'] = $info['mpeg']['audio']['sample_rate'];
        $info['audio']['dataformat'] = 'mp' . getid3_lib::array_max($Distribution['layer'], true);
        $info['fileformat'] = $info['audio']['dataformat'];

        return true;
    }


    public function getOnlyMPEGaudioInfo($avdataoffset, $BitrateHistogram = false)
    {
        // looks for synch, decodes MPEG audio header

        $info = & $this->getid3->info;

        static $MPEGaudioVersionLookup;
        static $MPEGaudioLayerLookup;
        static $MPEGaudioBitrateLookup;
        if (empty($MPEGaudioVersionLookup)) {
            $MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
            $MPEGaudioLayerLookup = self::MPEGaudioLayerArray();
            $MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();

        }

        fseek($this->getid3->fp, $avdataoffset, SEEK_SET);
        $sync_seek_buffer_size = min(128 * 1024, $info['avdataend'] - $avdataoffset);
        if ($sync_seek_buffer_size <= 0) {
            $info['error'][] = 'Invalid $sync_seek_buffer_size at offset ' . $avdataoffset;
            return false;
        }
        $header = fread($this->getid3->fp, $sync_seek_buffer_size);
        $sync_seek_buffer_size = strlen($header);
        $SynchSeekOffset = 0;
        while ($SynchSeekOffset < $sync_seek_buffer_size) {
            if ((($avdataoffset + $SynchSeekOffset) < $info['avdataend']) && !feof($this->getid3->fp)) {

                if ($SynchSeekOffset > $sync_seek_buffer_size) {
                    // if a synch's not found within the first 128k bytes, then give up
                    $info['error'][] = 'Could not find valid MPEG audio synch within the first ' . round($sync_seek_buffer_size / 1024) . 'kB';
                    if (isset($info['audio']['bitrate'])) {
                        unset($info['audio']['bitrate']);
                    }
                    if (isset($info['mpeg']['audio'])) {
                        unset($info['mpeg']['audio']);
                    }
                    if (empty($info['mpeg'])) {
                        unset($info['mpeg']);
                    }
                    return false;

                } elseif (feof($this->getid3->fp)) {

                    $info['error'][] = 'Could not find valid MPEG audio synch before end of file';
                    if (isset($info['audio']['bitrate'])) {
                        unset($info['audio']['bitrate']);
                    }
                    if (isset($info['mpeg']['audio'])) {
                        unset($info['mpeg']['audio']);
                    }
                    if (isset($info['mpeg']) && (!is_array($info['mpeg']) || (count($info['mpeg']) == 0))) {
                        unset($info['mpeg']);
                    }
                    return false;
                }
            }

            if (($SynchSeekOffset + 1) >= strlen($header)) {
                $info['error'][] = 'Could not find valid MPEG synch before end of file';
                return false;
            }

            if (($header{$SynchSeekOffset} == "\xFF") && ($header{($SynchSeekOffset + 1)} > "\xE0")) { // synch detected
                if (!isset($FirstFrameThisfileInfo) && !isset($info['mpeg']['audio'])) {
                    $FirstFrameThisfileInfo = $info;
                    $FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;
                    if (!$this->decodeMPEGaudioHeader($FirstFrameAVDataOffset, $FirstFrameThisfileInfo, false)) {
                        // if this is the first valid MPEG-audio frame, save it in case it's a VBR header frame and there's
                        // garbage between this frame and a valid sequence of MPEG-audio frames, to be restored below
                        unset($FirstFrameThisfileInfo);
                    }
                }

                $dummy = $info; // only overwrite real data if valid header found
                if ($this->decodeMPEGaudioHeader($avdataoffset + $SynchSeekOffset, $dummy, true)) {
                    $info = $dummy;
                    $info['avdataoffset'] = $avdataoffset + $SynchSeekOffset;
                    switch (isset($info['fileformat']) ? $info['fileformat'] : '') {
                        case '':
                        case 'id3':
                        case 'ape':
                        case 'mp3':
                            $info['fileformat'] = 'mp3';
                            $info['audio']['dataformat'] = 'mp3';
                            break;
                    }
                    if (isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr')) {
                        if (!(abs($info['audio']['bitrate'] - $FirstFrameThisfileInfo['audio']['bitrate']) <= 1)) {
                            // If there is garbage data between a valid VBR header frame and a sequence
                            // of valid MPEG-audio frames the VBR data is no longer discarded.
                            $info = $FirstFrameThisfileInfo;
                            $info['avdataoffset'] = $FirstFrameAVDataOffset;
                            $info['fileformat'] = 'mp3';
                            $info['audio']['dataformat'] = 'mp3';
                            $dummy = $info;
                            unset($dummy['mpeg']['audio']);
                            $GarbageOffsetStart = $FirstFrameAVDataOffset + $FirstFrameThisfileInfo['mpeg']['audio']['framelength'];
                            $GarbageOffsetEnd = $avdataoffset + $SynchSeekOffset;
                            if ($this->decodeMPEGaudioHeader($GarbageOffsetEnd, $dummy, true, true)) {
                                $info = $dummy;
                                $info['avdataoffset'] = $GarbageOffsetEnd;
                                $info['warning'][] = 'apparently-valid VBR header not used because could not find ' . GETID3_MP3_VALID_CHECK_FRAMES . ' consecutive MPEG-audio frames immediately after VBR header (garbage data for ' . ($GarbageOffsetEnd - $GarbageOffsetStart) . ' bytes between ' . $GarbageOffsetStart . ' and ' . $GarbageOffsetEnd . '), but did find valid CBR stream starting at ' . $GarbageOffsetEnd;
                            } else {
                                $info['warning'][] = 'using data from VBR header even though could not find ' . GETID3_MP3_VALID_CHECK_FRAMES . ' consecutive MPEG-audio frames immediately after VBR header (garbage data for ' . ($GarbageOffsetEnd - $GarbageOffsetStart) . ' bytes between ' . $GarbageOffsetStart . ' and ' . $GarbageOffsetEnd . ')';
                            }
                        }
                    }
                    if (isset($info['mpeg']['audio']['bitrate_mode']) && ($info['mpeg']['audio']['bitrate_mode'] == 'vbr') && !isset($info['mpeg']['audio']['VBR_method'])) {
                        // VBR file with no VBR header
                        $BitrateHistogram = true;
                    }

                    if ($BitrateHistogram) {

                        $info['mpeg']['audio']['stereo_distribution'] = array('stereo' => 0, 'joint stereo' => 0, 'dual channel' => 0, 'mono' => 0);
                        $info['mpeg']['audio']['version_distribution'] = array('1' => 0, '2' => 0, '2.5' => 0);

                        if ($info['mpeg']['audio']['version'] == '1') {
                            if ($info['mpeg']['audio']['layer'] == 3) {
                                $info['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 32000 => 0, 40000 => 0, 48000 => 0, 56000 => 0, 64000 => 0, 80000 => 0, 96000 => 0, 112000 => 0, 128000 => 0, 160000 => 0, 192000 => 0, 224000 => 0, 256000 => 0, 320000 => 0);
                            } elseif ($info['mpeg']['audio']['layer'] == 2) {
                                $info['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 32000 => 0, 48000 => 0, 56000 => 0, 64000 => 0, 80000 => 0, 96000 => 0, 112000 => 0, 128000 => 0, 160000 => 0, 192000 => 0, 224000 => 0, 256000 => 0, 320000 => 0, 384000 => 0);
                            } elseif ($info['mpeg']['audio']['layer'] == 1) {
                                $info['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 32000 => 0, 64000 => 0, 96000 => 0, 128000 => 0, 160000 => 0, 192000 => 0, 224000 => 0, 256000 => 0, 288000 => 0, 320000 => 0, 352000 => 0, 384000 => 0, 416000 => 0, 448000 => 0);
                            }
                        } elseif ($info['mpeg']['audio']['layer'] == 1) {
                            $info['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 32000 => 0, 48000 => 0, 56000 => 0, 64000 => 0, 80000 => 0, 96000 => 0, 112000 => 0, 128000 => 0, 144000 => 0, 160000 => 0, 176000 => 0, 192000 => 0, 224000 => 0, 256000 => 0);
                        } else {
                            $info['mpeg']['audio']['bitrate_distribution'] = array('free' => 0, 8000 => 0, 16000 => 0, 24000 => 0, 32000 => 0, 40000 => 0, 48000 => 0, 56000 => 0, 64000 => 0, 80000 => 0, 96000 => 0, 112000 => 0, 128000 => 0, 144000 => 0, 160000 => 0);
                        }

                        $dummy = array('error' => $info['error'], 'warning' => $info['warning'], 'avdataend' => $info['avdataend'], 'avdataoffset' => $info['avdataoffset']);
                        $synchstartoffset = $info['avdataoffset'];
                        fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);

                        // you can play with these numbers:
                        $max_frames_scan = 50000;
                        $max_scan_segments = 10;

                        // don't play with these numbers:
                        $FastMode = false;
                        $SynchErrorsFound = 0;
                        $frames_scanned = 0;
                        $this_scan_segment = 0;
                        $frames_scan_per_segment = ceil($max_frames_scan / $max_scan_segments);
                        $pct_data_scanned = 0;
                        for ($current_segment = 0; $current_segment < $max_scan_segments; $current_segment++) {
                            $frames_scanned_this_segment = 0;
                            if (ftell($this->getid3->fp) >= $info['avdataend']) {
                                break;
                            }
                            $scan_start_offset[$current_segment] = max(ftell($this->getid3->fp), $info['avdataoffset'] + round($current_segment * (($info['avdataend'] - $info['avdataoffset']) / $max_scan_segments)));
                            if ($current_segment > 0) {
                                fseek($this->getid3->fp, $scan_start_offset[$current_segment], SEEK_SET);
                                $buffer_4k = fread($this->getid3->fp, 4096);
                                for ($j = 0; $j < (strlen($buffer_4k) - 4); $j++) {
                                    if (($buffer_4k{$j} == "\xFF") && ($buffer_4k{($j + 1)} > "\xE0")) { // synch detected
                                        if ($this->decodeMPEGaudioHeader($scan_start_offset[$current_segment] + $j, $dummy, false, false, $FastMode)) {
                                            $calculated_next_offset = $scan_start_offset[$current_segment] + $j + $dummy['mpeg']['audio']['framelength'];
                                            if ($this->decodeMPEGaudioHeader($calculated_next_offset, $dummy, false, false, $FastMode)) {
                                                $scan_start_offset[$current_segment] += $j;
                                                break;
                                            }
                                        }
                                    }
                                }
                            }
                            $synchstartoffset = $scan_start_offset[$current_segment];
                            while ($this->decodeMPEGaudioHeader($synchstartoffset, $dummy, false, false, $FastMode)) {
                                $FastMode = true;
                                $thisframebitrate = $MPEGaudioBitrateLookup[$MPEGaudioVersionLookup[$dummy['mpeg']['audio']['raw']['version']]][$MPEGaudioLayerLookup[$dummy['mpeg']['audio']['raw']['layer']]][$dummy['mpeg']['audio']['raw']['bitrate']];

                                if (empty($dummy['mpeg']['audio']['framelength'])) {
                                    $SynchErrorsFound++;
                                    $synchstartoffset++;
                                } else {
                                    getid3_lib::safe_inc($info['mpeg']['audio']['bitrate_distribution'][$thisframebitrate]);
                                    getid3_lib::safe_inc($info['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']]);
                                    getid3_lib::safe_inc($info['mpeg']['audio']['version_distribution'][$dummy['mpeg']['audio']['version']]);
                                    $synchstartoffset += $dummy['mpeg']['audio']['framelength'];
                                }
                                $frames_scanned++;
                                if ($frames_scan_per_segment && (++$frames_scanned_this_segment >= $frames_scan_per_segment)) {
                                    $this_pct_scanned = (ftell($this->getid3->fp) - $scan_start_offset[$current_segment]) / ($info['avdataend'] - $info['avdataoffset']);
                                    if (($current_segment == 0) && (($this_pct_scanned * $max_scan_segments) >= 1)) {
                                        // file likely contains < $max_frames_scan, just scan as one segment
                                        $max_scan_segments = 1;
                                        $frames_scan_per_segment = $max_frames_scan;
                                    } else {
                                        $pct_data_scanned += $this_pct_scanned;
                                        break;
                                    }
                                }
                            }
                        }
                        if ($pct_data_scanned > 0) {
                            $info['warning'][] = 'too many MPEG audio frames to scan, only scanned ' . $frames_scanned . ' frames in ' . $max_scan_segments . ' segments (' . number_format($pct_data_scanned * 100, 1) . '% of file) and extrapolated distribution, playtime and bitrate may be incorrect.';
                            foreach ($info['mpeg']['audio'] as $key1 => $value1) {
                                if (!preg_match('#_distribution$#i', $key1)) {
                                    continue;
                                }
                                foreach ($value1 as $key2 => $value2) {
                                    $info['mpeg']['audio'][$key1][$key2] = round($value2 / $pct_data_scanned);
                                }
                            }
                        }

                        if ($SynchErrorsFound > 0) {
                            $info['warning'][] = 'Found ' . $SynchErrorsFound . ' synch errors in histogram analysis';
                            //return false;
                        }

                        $bittotal = 0;
                        $framecounter = 0;
                        foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitratevalue => $bitratecount) {
                            $framecounter += $bitratecount;
                            if ($bitratevalue != 'free') {
                                $bittotal += ($bitratevalue * $bitratecount);
                            }
                        }
                        if ($framecounter == 0) {
                            $info['error'][] = 'Corrupt MP3 file: framecounter == zero';
                            return false;
                        }
                        $info['mpeg']['audio']['frame_count'] = getid3_lib::CastAsInt($framecounter);
                        $info['mpeg']['audio']['bitrate'] = ($bittotal / $framecounter);

                        $info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];


                        // Definitively set VBR vs CBR, even if the Xing/LAME/VBRI header says differently
                        $distinct_bitrates = 0;
                        foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitrate_value => $bitrate_count) {
                            if ($bitrate_count > 0) {
                                $distinct_bitrates++;
                            }
                        }
                        if ($distinct_bitrates > 1) {
                            $info['mpeg']['audio']['bitrate_mode'] = 'vbr';
                        } else {
                            $info['mpeg']['audio']['bitrate_mode'] = 'cbr';
                        }
                        $info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];

                    }

                    break; // exit while()
                }
            }

            $SynchSeekOffset++;
            if (($avdataoffset + $SynchSeekOffset) >= $info['avdataend']) {
                // end of file/data

                if (empty($info['mpeg']['audio'])) {

                    $info['error'][] = 'could not find valid MPEG synch before end of file';
                    if (isset($info['audio']['bitrate'])) {
                        unset($info['audio']['bitrate']);
                    }
                    if (isset($info['mpeg']['audio'])) {
                        unset($info['mpeg']['audio']);
                    }
                    if (isset($info['mpeg']) && (!is_array($info['mpeg']) || empty($info['mpeg']))) {
                        unset($info['mpeg']);
                    }
                    return false;

                }
                break;
            }

        }
        $info['audio']['channels'] = $info['mpeg']['audio']['channels'];
        $info['audio']['channelmode'] = $info['mpeg']['audio']['channelmode'];
        $info['audio']['sample_rate'] = $info['mpeg']['audio']['sample_rate'];
        return true;
    }


    public static function MPEGaudioVersionArray()
    {
        static $MPEGaudioVersion = array('2.5', false, '2', '1');
        return $MPEGaudioVersion;
    }

    public static function MPEGaudioLayerArray()
    {
        static $MPEGaudioLayer = array(false, 3, 2, 1);
        return $MPEGaudioLayer;
    }

    public static function MPEGaudioBitrateArray()
    {
        static $MPEGaudioBitrate;
        if (empty($MPEGaudioBitrate)) {
            $MPEGaudioBitrate = array(
                '1' => array(1 => array('free', 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000, 288000, 320000, 352000, 384000, 416000, 448000),
                    2 => array('free', 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000, 384000),
                    3 => array('free', 32000, 40000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000)
                ),

                '2' => array(1 => array('free', 32000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 144000, 160000, 176000, 192000, 224000, 256000),
                    2 => array('free', 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000, 96000, 112000, 128000, 144000, 160000),
                )
            );
            $MPEGaudioBitrate['2'][3] = $MPEGaudioBitrate['2'][2];
            $MPEGaudioBitrate['2.5'] = $MPEGaudioBitrate['2'];
        }
        return $MPEGaudioBitrate;
    }

    public static function MPEGaudioFrequencyArray()
    {
        static $MPEGaudioFrequency;
        if (empty($MPEGaudioFrequency)) {
            $MPEGaudioFrequency = array(
                '1' => array(44100, 48000, 32000),
                '2' => array(22050, 24000, 16000),
                '2.5' => array(11025, 12000, 8000)
            );
        }
        return $MPEGaudioFrequency;
    }

    public static function MPEGaudioChannelModeArray()
    {
        static $MPEGaudioChannelMode = array('stereo', 'joint stereo', 'dual channel', 'mono');
        return $MPEGaudioChannelMode;
    }

    public static function MPEGaudioModeExtensionArray()
    {
        static $MPEGaudioModeExtension;
        if (empty($MPEGaudioModeExtension)) {
            $MPEGaudioModeExtension = array(
                1 => array('4-31', '8-31', '12-31', '16-31'),
                2 => array('4-31', '8-31', '12-31', '16-31'),
                3 => array('', 'IS', 'MS', 'IS+MS')
            );
        }
        return $MPEGaudioModeExtension;
    }

    public static function MPEGaudioEmphasisArray()
    {
        static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');
        return $MPEGaudioEmphasis;
    }

    public static function MPEGaudioHeaderBytesValid($head4, $allowBitrate15 = false)
    {
        return self::MPEGaudioHeaderValid(self::MPEGaudioHeaderDecode($head4), false, $allowBitrate15);
    }

    public static function MPEGaudioHeaderValid($rawarray, $echoerrors = false, $allowBitrate15 = false)
    {
        if (($rawarray['synch'] & 0x0FFE) != 0x0FFE) {
            return false;
        }

        static $MPEGaudioVersionLookup;
        static $MPEGaudioLayerLookup;
        static $MPEGaudioBitrateLookup;
        static $MPEGaudioFrequencyLookup;
        static $MPEGaudioChannelModeLookup;
        static $MPEGaudioModeExtensionLookup;
        static $MPEGaudioEmphasisLookup;
        if (empty($MPEGaudioVersionLookup)) {
            $MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
            $MPEGaudioLayerLookup = self::MPEGaudioLayerArray();
            $MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
            $MPEGaudioFrequencyLookup = self::MPEGaudioFrequencyArray();
            $MPEGaudioChannelModeLookup = self::MPEGaudioChannelModeArray();
            $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
            $MPEGaudioEmphasisLookup = self::MPEGaudioEmphasisArray();
        }

        if (isset($MPEGaudioVersionLookup[$rawarray['version']])) {
            $decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];
        } else {
            echo($echoerrors ? "\n" . 'invalid Version (' . $rawarray['version'] . ')' : '');
            return false;
        }
        if (isset($MPEGaudioLayerLookup[$rawarray['layer']])) {
            $decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];
        } else {
            echo($echoerrors ? "\n" . 'invalid Layer (' . $rawarray['layer'] . ')' : '');
            return false;
        }
        if (!isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']])) {
            echo($echoerrors ? "\n" . 'invalid Bitrate (' . $rawarray['bitrate'] . ')' : '');
            if ($rawarray['bitrate'] == 15) {
                // known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
                // let it go through here otherwise file will not be identified
                if (!$allowBitrate15) {
                    return false;
                }
            } else {
                return false;
            }
        }
        if (!isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']])) {
            echo($echoerrors ? "\n" . 'invalid Frequency (' . $rawarray['sample_rate'] . ')' : '');
            return false;
        }
        if (!isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']])) {
            echo($echoerrors ? "\n" . 'invalid ChannelMode (' . $rawarray['channelmode'] . ')' : '');
            return false;
        }
        if (!isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']])) {
            echo($echoerrors ? "\n" . 'invalid Mode Extension (' . $rawarray['modeextension'] . ')' : '');
            return false;
        }
        if (!isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']])) {
            echo($echoerrors ? "\n" . 'invalid Emphasis (' . $rawarray['emphasis'] . ')' : '');
            return false;
        }
        // These are just either set or not set, you can't mess that up :)
        // $rawarray['protection'];
        // $rawarray['padding'];
        // $rawarray['private'];
        // $rawarray['copyright'];
        // $rawarray['original'];

        return true;
    }

    public static function MPEGaudioHeaderDecode($Header4Bytes)
    {
        // AAAA AAAA  AAAB BCCD  EEEE FFGH  IIJJ KLMM
        // A - Frame sync (all bits set)
        // B - MPEG Audio version ID
        // C - Layer description
        // D - Protection bit
        // E - Bitrate index
        // F - Sampling rate frequency index
        // G - Padding bit
        // H - Private bit
        // I - Channel Mode
        // J - Mode extension (Only if Joint stereo)
        // K - Copyright
        // L - Original
        // M - Emphasis

        if (strlen($Header4Bytes) != 4) {
            return false;
        }

        $MPEGrawHeader['synch'] = (getid3_lib::BigEndian2Int(substr($Header4Bytes, 0, 2)) & 0xFFE0) >> 4;
        $MPEGrawHeader['version'] = (ord($Header4Bytes{1}) & 0x18) >> 3; //    BB
        $MPEGrawHeader['layer'] = (ord($Header4Bytes{1}) & 0x06) >> 1; //      CC
        $MPEGrawHeader['protection'] = (ord($Header4Bytes{1}) & 0x01); //        D
        $MPEGrawHeader['bitrate'] = (ord($Header4Bytes{2}) & 0xF0) >> 4; // EEEE
        $MPEGrawHeader['sample_rate'] = (ord($Header4Bytes{2}) & 0x0C) >> 2; //     FF
        $MPEGrawHeader['padding'] = (ord($Header4Bytes{2}) & 0x02) >> 1; //       G
        $MPEGrawHeader['private'] = (ord($Header4Bytes{2}) & 0x01); //        H
        $MPEGrawHeader['channelmode'] = (ord($Header4Bytes{3}) & 0xC0) >> 6; // II
        $MPEGrawHeader['modeextension'] = (ord($Header4Bytes{3}) & 0x30) >> 4; //   JJ
        $MPEGrawHeader['copyright'] = (ord($Header4Bytes{3}) & 0x08) >> 3; //     K
        $MPEGrawHeader['original'] = (ord($Header4Bytes{3}) & 0x04) >> 2; //      L
        $MPEGrawHeader['emphasis'] = (ord($Header4Bytes{3}) & 0x03); //       MM

        return $MPEGrawHeader;
    }

    public static function MPEGaudioFrameLength(&$bitrate, &$version, &$layer, $padding, &$samplerate)
    {
        static $AudioFrameLengthCache = array();

        if (!isset($AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate])) {
            $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = false;
            if ($bitrate != 'free') {

                if ($version == '1') {

                    if ($layer == '1') {

                        // For Layer I slot is 32 bits long
                        $FrameLengthCoefficient = 48;
                        $SlotLength = 4;

                    } else { // Layer 2 / 3

                        // for Layer 2 and Layer 3 slot is 8 bits long.
                        $FrameLengthCoefficient = 144;
                        $SlotLength = 1;

                    }

                } else { // MPEG-2 / MPEG-2.5

                    if ($layer == '1') {

                        // For Layer I slot is 32 bits long
                        $FrameLengthCoefficient = 24;
                        $SlotLength = 4;

                    } elseif ($layer == '2') {

                        // for Layer 2 and Layer 3 slot is 8 bits long.
                        $FrameLengthCoefficient = 144;
                        $SlotLength = 1;

                    } else { // layer 3

                        // for Layer 2 and Layer 3 slot is 8 bits long.
                        $FrameLengthCoefficient = 72;
                        $SlotLength = 1;

                    }

                }

                // FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
                if ($samplerate > 0) {
                    $NewFramelength = ($FrameLengthCoefficient * $bitrate) / $samplerate;
                    $NewFramelength = floor($NewFramelength / $SlotLength) * $SlotLength; // round to next-lower multiple of SlotLength (1 byte for Layer 2/3, 4 bytes for Layer I)
                    if ($padding) {
                        $NewFramelength += $SlotLength;
                    }
                    $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = (int)$NewFramelength;
                }
            }
        }
        return $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate];
    }

    public static function ClosestStandardMP3Bitrate($bit_rate)
    {
        static $standard_bit_rates = array(320000, 256000, 224000, 192000, 160000, 128000, 112000, 96000, 80000, 64000, 56000, 48000, 40000, 32000, 24000, 16000, 8000);
        static $bit_rate_table = array(0 => '-');
        $round_bit_rate = intval(round($bit_rate, -3));
        if (!isset($bit_rate_table[$round_bit_rate])) {
            if ($round_bit_rate > max($standard_bit_rates)) {
                $bit_rate_table[$round_bit_rate] = round($bit_rate, 2 - strlen($bit_rate));
            } else {
                $bit_rate_table[$round_bit_rate] = max($standard_bit_rates);
                foreach ($standard_bit_rates as $standard_bit_rate) {
                    if ($round_bit_rate >= $standard_bit_rate + (($bit_rate_table[$round_bit_rate] - $standard_bit_rate) / 2)) {
                        break;
                    }
                    $bit_rate_table[$round_bit_rate] = $standard_bit_rate;
                }
            }
        }
        return $bit_rate_table[$round_bit_rate];
    }

    public static function XingVBRidOffset($version, $channelmode)
    {
        static $XingVBRidOffsetCache = array();
        if (empty($XingVBRidOffset)) {
            $XingVBRidOffset = array(
                '1' => array('mono' => 0x15, // 4 + 17 = 21
                    'stereo' => 0x24, // 4 + 32 = 36
                    'joint stereo' => 0x24,
                    'dual channel' => 0x24
                ),

                '2' => array('mono' => 0x0D, // 4 +  9 = 13
                    'stereo' => 0x15, // 4 + 17 = 21
                    'joint stereo' => 0x15,
                    'dual channel' => 0x15
                ),

                '2.5' => array('mono' => 0x15,
                    'stereo' => 0x15,
                    'joint stereo' => 0x15,
                    'dual channel' => 0x15
                )
            );
        }
        return $XingVBRidOffset[$version][$channelmode];
    }

    public static function LAMEvbrMethodLookup($VBRmethodID)
    {
        static $LAMEvbrMethodLookup = array(
            0x00 => 'unknown',
            0x01 => 'cbr',
            0x02 => 'abr',
            0x03 => 'vbr-old / vbr-rh',
            0x04 => 'vbr-new / vbr-mtrh',
            0x05 => 'vbr-mt',
            0x06 => 'vbr (full vbr method 4)',
            0x08 => 'cbr (constant bitrate 2 pass)',
            0x09 => 'abr (2 pass)',
            0x0F => 'reserved'
        );
        return (isset($LAMEvbrMethodLookup[$VBRmethodID]) ? $LAMEvbrMethodLookup[$VBRmethodID] : '');
    }

    public static function LAMEmiscStereoModeLookup($StereoModeID)
    {
        static $LAMEmiscStereoModeLookup = array(
            0 => 'mono',
            1 => 'stereo',
            2 => 'dual mono',
            3 => 'joint stereo',
            4 => 'forced stereo',
            5 => 'auto',
            6 => 'intensity stereo',
            7 => 'other'
        );
        return (isset($LAMEmiscStereoModeLookup[$StereoModeID]) ? $LAMEmiscStereoModeLookup[$StereoModeID] : '');
    }

    public static function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID)
    {
        static $LAMEmiscSourceSampleFrequencyLookup = array(
            0 => '<= 32 kHz',
            1 => '44.1 kHz',
            2 => '48 kHz',
            3 => '> 48kHz'
        );
        return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');
    }

    public static function LAMEsurroundInfoLookup($SurroundInfoID)
    {
        static $LAMEsurroundInfoLookup = array(
            0 => 'no surround info',
            1 => 'DPL encoding',
            2 => 'DPL2 encoding',
            3 => 'Ambisonic encoding'
        );
        return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');
    }

    public static function LAMEpresetUsedLookup($LAMEtag)
    {

        if ($LAMEtag['preset_used_id'] == 0) {
            // no preset used (LAME >=3.93)
            // no preset recorded (LAME <3.93)
            return '';
        }
        $LAMEpresetUsedLookup = array();

        /////  THIS PART CANNOT BE STATIC .
        for ($i = 8; $i <= 320; $i++) {
            switch ($LAMEtag['vbr_method']) {
                case 'cbr':
                    $LAMEpresetUsedLookup[$i] = '--alt-preset ' . $LAMEtag['vbr_method'] . ' ' . $i;
                    break;
                case 'abr':
                default: // other VBR modes shouldn't be here(?)
                    $LAMEpresetUsedLookup[$i] = '--alt-preset ' . $i;
                    break;
            }
        }

        // named old-style presets (studio, phone, voice, etc) are handled in GuessEncoderOptions()

        // named alt-presets
        $LAMEpresetUsedLookup[1000] = '--r3mix';
        $LAMEpresetUsedLookup[1001] = '--alt-preset standard';
        $LAMEpresetUsedLookup[1002] = '--alt-preset extreme';
        $LAMEpresetUsedLookup[1003] = '--alt-preset insane';
        $LAMEpresetUsedLookup[1004] = '--alt-preset fast standard';
        $LAMEpresetUsedLookup[1005] = '--alt-preset fast extreme';
        $LAMEpresetUsedLookup[1006] = '--alt-preset medium';
        $LAMEpresetUsedLookup[1007] = '--alt-preset fast medium';

        // LAME 3.94 additions/changes
        $LAMEpresetUsedLookup[1010] = '--preset portable'; // 3.94a15 Oct 21 2003
        $LAMEpresetUsedLookup[1015] = '--preset radio'; // 3.94a15 Oct 21 2003

        $LAMEpresetUsedLookup[320] = '--preset insane'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[410] = '-V9';
        $LAMEpresetUsedLookup[420] = '-V8';
        $LAMEpresetUsedLookup[440] = '-V6';
        $LAMEpresetUsedLookup[430] = '--preset radio'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[450] = '--preset ' . (($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '') . 'portable'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[460] = '--preset ' . (($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '') . 'medium'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[470] = '--r3mix'; // 3.94b1  Dec 18 2003
        $LAMEpresetUsedLookup[480] = '--preset ' . (($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '') . 'standard'; // 3.94a15 Nov 12 2003
        $LAMEpresetUsedLookup[490] = '-V1';
        $LAMEpresetUsedLookup[500] = '--preset ' . (($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '') . 'extreme'; // 3.94a15 Nov 12 2003

        return (isset($LAMEpresetUsedLookup[$LAMEtag['preset_used_id']]) ? $LAMEpresetUsedLookup[$LAMEtag['preset_used_id']] : 'new/unknown preset: ' . $LAMEtag['preset_used_id'] . ' - report to info@getid3.org');
    }

}
